Paliperidone is used in adults to treat schizophrenia. Paliperidone is also used alone or with other medicines to treat schizoaffective disorder in adults.

Paliperidone may also be used for purposes not listed in this medication guide.

You should not use this medicine if you are allergic to paliperidone or to risperidone (Risperdal).

Paliperidone may increase the risk of death in older adults with dementia-related psychosis and is not approved for this use.

High doses or long-term use of paliperidone can cause a serious movement disorder that may not be reversible. The longer you use paliperidone, the more likely you are to develop this disorder, especially if you are a woman or an older adult.

Before you receive your first injection, tell your doctor if you have never taken oral (by mouth) paliperidone or risperidone.

Tell your doctor if you have ever had:

• heart problems, or a heart attack;
• long QT syndrome (in you or a family member);
• high or low blood pressure, or fainting spells;
• low white blood cell (WBC) counts;
• a serious neurologic disorder caused by taking an antipsychotic medicine;
• uncontrolled muscle movements in your face (chewing, lip smacking, frowning, tongue movement, blinking or eye movement);
• seizures or epilepsy;
• an electrolyte imbalance (such as low blood levels of potassium or magnesium);
• diabetes (in you or a family member);
• cancer of the breast; or
• liver or kidney disease.

It is not known if paliperidone will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Using antipsychotic medicine in the last 3 months of pregnancy may cause serious problems in the newborn. Tell your doctor right away if you get pregnant.

If you are pregnant, your name may be listed on a pregnancy registry to track the effects of paliperidone on the baby.

Ask a doctor if it is safe to breastfeed while using this medicine.

Use Invega Hafyera (Intramuscular) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Tell your doctor right away if you have any of these signs of a serious movement disorder:

• tremors or shaking in your arms or legs;
• uncontrolled muscle movements in your face (chewing, lip smacking, frowning, tongue movement, blinking or eye movement); or
• any new or unusual muscle movements you cannot control.

Call your doctor at once if you have:

• low blood pressure, fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness (like you might pass out);
• problems with thinking or feeling unsteady;
• trouble swallowing;
• seizure;
• breast swelling and tenderness, nipple discharge;
• high cholesterol, weight gain;
• fever, chills, sore throat, mouth sores, feeling light-headed;
• irregular blood cell counts;
• high blood sugar--increased thirst, increased urination, dry mouth, fruity breath odor;
• severe nervous system reaction--very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out;
• impotence, or erection that is painful or lasts longer than 4 hours; or
• changes in your menstrual periods.

Common side effects may include:

• headache, dizziness, drowsiness;
• cold symptoms such as stuffy nose, sneezing, sore throat;
• feeling restless or excited;
• muscle stiffness, tremors or shaking;
• uncontrolled muscle movements, problems with speech or walking;
• problems with balance or eye movement;
• weight gain;
• upset stomach, constipation;
• fast heart rate; or
• pain, bruising, swelling, or irritation where the medicine was injected.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Avoid drinking alcohol. Dangerous side effects could occur.

Avoid becoming overheated or dehydrated during exercise, in hot weather, or by not drinking enough fluids. Follow your doctor's instructions about the type and amount of liquids you should drink.

Avoid driving or hazardous activity until you know how this medicine will affect you. Dizziness or drowsiness can cause falls, accidents, or severe injuries.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.